In recent times, there has been a rapid increase in use of technologies such as virtual reality, augmented reality, and so forth, for presenting a simulated environment (or a virtual world) to a user. Typically, the user uses a specialized device (for example, such as a virtual reality device, an augmented reality device, and the like) for experiencing such a simulated environment. In use, the user generally wears (namely, supports) the specialized device on his/her head.
Nowadays, such specialized devices often employ a technique such as gaze-tracking (namely, eye tracking) to determine a gaze direction of the user. Typically, the gaze-tracking is associated with determination of position of pupils of eyes of the user. Generally, an illumination source is employed for emitting light towards the user's eyes, and a camera is employed for capturing an image depicting reflection(s) of emitted light from the user's eyes. Furthermore, the reflection(s) emitted light from the user's eyes is used as a frame of reference for determining the position of the pupils of the user's eyes with respect thereto.
However, there exist a number of limitations associated with implementation of the aforementioned gaze-tracking techniques. Firstly, the camera is limited in its ability to fully focus a convex object such as the user's eye. As a result, there may exist blurriness associated with certain regions of the user's eye, within the captured image. Consequently, such blurriness severely limits accuracy of the determined gaze direction of the user. Secondly, a position of the camera is generally changed by employing an actuator, to accurately capture the reflection(s) of the emitted light from the user's eyes. In such a case, a magnitude and/or a direction of movement of the camera, is required to be precise. However, due to limited size of the head mounted display apparatus, moving the camera in a desired direction may be cumbersome. Furthermore, arranging the actuator in connection with the camera increases complexity associated with physical design of the aforesaid specialized devices. Consequently, there exists several optical design constraints associated with the specialized device for implementing such gaze-tracking techniques. Thirdly, the captured image of the reflection(s) of the emitted light from the user's eyes often depicts a side perspective view of the user's eye. Such a side perspective image can also lead to inaccuracies in determining the gaze direction of the user.
Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks associated with conventional equipment and techniques for gaze-tracking.